From 0d8cfeeef3f5a5966abce1903f80308be33280cb Mon Sep 17 00:00:00 2001
From: Chunfeng Yun <chunfeng.yun@mediatek.com>
Date: Tue, 2 Nov 2021 10:50:04 +0800
Subject: [PATCH] usb: xhci-mtk: fix random remote wakeup
Git-commit: 0d8cfeeef3f5a5966abce1903f80308be33280cb
References: jsc#PED-531
Patch-mainline: v5.17-rc1
Some platforms, e.g. 8183/8192, use low level latch way to keep
wakeup signal, it may latch a wrong signal if debounce more time,
and enable wakeup function earlier.
____________________
ip_sleep ____/ \_____________
___________________
wakeup_signal ____________/ \______
_______________________________
wakeup_en _______/
^ ^
|(1) |(2)
latch wakeup_signal mistakenly at (1), should latch it at (2);
Workaround: delay about 100us to enable wakeup, meanwhile decrease
debounce time.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20211102025004.29156-2-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/usb/host/xhci-mtk.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 8b98de409c71..91738af0ab14 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -245,11 +245,12 @@ static int xhci_mtk_host_disable(struct xhci_hcd_mtk *mtk)
/* wait for host ip to sleep */
ret = readl_poll_timeout(&ippc->ip_pw_sts1, value,
(value & STS1_IP_SLEEP_STS), 100, 100000);
- if (ret) {
+ if (ret)
dev_err(mtk->dev, "ip sleep failed!!!\n");
- return ret;
- }
- return 0;
+ else /* workaound for platforms using low level latch */
+ usleep_range(100, 200);
+
+ return ret;
}
static int xhci_mtk_ssusb_config(struct xhci_hcd_mtk *mtk)
@@ -300,7 +301,7 @@ static void usb_wakeup_ip_sleep_set(struct xhci_hcd_mtk *mtk, bool enable)
case SSUSB_UWK_V1_1:
reg = mtk->uwk_reg_base + PERI_WK_CTRL0;
msk = WC0_IS_EN | WC0_IS_C(0xf) | WC0_IS_P;
- val = enable ? (WC0_IS_EN | WC0_IS_C(0x8)) : 0;
+ val = enable ? (WC0_IS_EN | WC0_IS_C(0x1)) : 0;
break;
case SSUSB_UWK_V1_2:
reg = mtk->uwk_reg_base + PERI_WK_CTRL0;
--
2.35.3